The present invention relates to climbing shuttering for use in casting concrete structures, such as dams and earth supporting walls, which are poured in a plurality of successive layers.
In particular, the invention relates to climbing shuttering of the type having at least one shuttering panel which defines a vertical or inclined surface of part of a concrete structure in the process of being cast, and at least one lifting device connected to the or each shuttering panel, which can be connected to an underlying part of the structure, which has already been cast and hardened, in order to raise the shuttering panel to a suitable position for shuttering the volume above, which is next to be cast.
Known such climbing shuttering comprises at least one shuttering panel for defining a vertical or inclined surface of a part of a structure being cast, and at least one support and elevation device for said at least one panel, said support and elevation device including: a main frame, means connecting said main frame to said panel, first fixing means for removably attaching one of said main frame, said panel, said main frame and said panel to said structure being cast, an upright member longitudinally displaceable with respect to said main frame, second fixing means for removably attaching said upright member to said structure being cast, at a level below said main frame, actuator means interconnecting said main frame and said upright member and operating when actuated to effect relative displacement between said upright member and said main frame, and separation means for displacing said panel toward or away from said structure being cast. In such known climbing shuttering the means for separating the or each shuttering panel from the hardened part of the concrete structure prior to raising the panel or panels consists, for each panel, either of an hydraulic or screw operated actuator having a thrust plate or the like, which is mounted on the shuttering panel and operates to exert a direct thrust on the hardened surface of the concrete structure, or an actuator which interconnects the panel and its associated frame and which operates to exert on the panel a pull towards the frame in order to move it away from the hardened surface of the concrete structure.
Both these known separation means only produce a limited and temporary displacement of the panels from the hardened surface of the concrete structure, for the purpose of breaking the bond formed between the panel and the concrete during hardening, to permit the panel to be raised. During the raising of the shuttering panel there is no certainty that the panel surface facing the concrete will not be scratched against the hardened concrete with consequent wear and scoring damage of the panel. In devices in which the thrust plate of the actuator acts directly on the hardened concrete surface, it is possible to avoid scratching of the panel, but in this case it is the thrust plate or like element of the actuator which is scratched and suffers consequent wear.